1. Technical Field of the Invention
The present invention relates generally to electrical generation and energy conversion devices, and more particularly to a fluid-powered energy conversion device that converts the energy of wind or flowing water to mechanical or electrical energy.
2. Description of Related Art
The use of wind or flowing water to provide power for various uses dates back many centuries. In modern times, wind and water have been used to generate electricity. Hydroelectric generating plants have been used to generate large quantities of electrical energy for widespread distribution. However, this requires major permanent environmental changes to the areas where dams are built and reservoirs rise. Wind-powered devices, in general, have been used to perform mechanical work, or to generate electricity, only on a limited scale. With the ever increasing demand for additional or alternative energy sources, all possible sources are being given more scrutiny. This is particularly true for sources that are non-polluting and inexhaustible. Free-flowing hydro-electric and wind-powered systems provide such sources, and the capturing of increased energy from wind and water has received much consideration.
Commercial hydro-electric and wind-powered electrical generation devices that are currently in use, however, have several disadvantages. Wind-powered devices, in particular, are expensive, inefficient, dangerous, noisy, and unpleasant to be around. To capture a large volume of wind, existing wind-powered devices are very large. As a result, they cannot be distributed throughout population centers, but must be installed some distance away. Then, like dams with hydro-electric generators, the electrical energy they generate must be transmitted, at considerable cost and with considerable lost energy, to the population centers where the energy is needed.
It would be desirable to distribute smaller water-powered and wind-powered units throughout the population centers. For example, it would be desirable to have a wind-powered unit for each building structure, thus distributing the generating capacity over the entire area, and making the energy supply less vulnerable to local events such as storms or earthquakes. Such distributed generation would also solve the most common and valid objection to wind power, that is, that the wind does not always blow. In a large geographical area, however, wind is almost always blowing somewhere. Therefore, with wind-powered generators distributed throughout the area, power could be generated in the areas where the wind is blowing, and then transmitted to the rest of the power grid. However, with existing technology, smaller units suitable for distributing throughout a population area are not efficient enough to provide a sufficient amount of energy to power a structure such as a house or office building. In addition, such units are visually obtrusive and noisy, making them unsuitable for use in residential or other highly populated settings.
Existing wind-powered electrical generation devices commonly utilize a propeller mounted on the horizontal shaft of a generator which, in turn, is mounted at the top of a tower. This is an inefficient design because energy is extracted from the wind by reducing the wind velocity as it passes through the propeller. This creates a pocket of slow-moving air centered behind the propeller, which the ambient wind blows around. Therefore, only the outer portion of the propeller blades use the wind efficiently.
To counter this effect, modern windmill designs utilize extremely long propeller blades. The use of such massive blades, however, has its own disadvantages. First, the propellers are known to kill or injure thousands of large birds each year. Second, the massive blades can be dangerous if the device fails structurally and the propeller breaks loose. In this case, the propeller can fly a considerable distance and cause serious damage or injury to anything or anyone in its path. Third, the propeller design contains an inherent gravitational imbalance. The rising blades on one side of the propeller""s hub are opposing gravity, while the descending blades on the other side of the hub are falling with gravity. This imbalance creates a great deal of vibration and stress on the device. At great expense, consequently, the device must be structurally enhanced to withstand the vibration and stress, and thus avoid frequent maintenance and/or replacement.
It would therefore be advantageous to have a fluid-powered energy conversion device that overcomes the shortcomings of existing devices. Such a device could utilize wind energy or the energy of flowing water to provide mechanical energy or electrical energy. The present invention provides such a device.
In one aspect, the present invention is a fluid-powered energy conversion device for converting energy in a moving fluid into mechanical energy. The device includes a rigid cylindrical frame having an upstream annular chamber and a downstream annular chamber. Each of the chambers has sides that are open to allow entry of the moving fluid. A first plurality of baffles are longitudinally mounted in the upstream chamber, and operate to create in the upstream chamber, an upstream drive vortex rotating in a first direction when the moving fluid enters the upstream chamber through the upstream chamber""s open sides. A first plurality of hinged louvers are positioned in the openings between the first plurality of baffles, and encircle an upstream central vortex chamber centered around a central longitudinal axis of the device. The first plurality of louvers permit entry of the moving fluid into the upstream central vortex chamber only when the fluid is rotating in the first direction. They also prevent the fluid from exiting the upstream central vortex chamber through the sides of the device. The device also includes a floor of the upstream annular chamber that slopes toward the downstream chamber as the floor approaches the central longitudinal axis of the device. The sloping floor causes the drive vortex to flow downstream through the upstream central vortex chamber and pass through a central aperture located between the upstream annular chamber and the downstream annular chamber. A longitudinal drive shaft is centrally mounted in the central aperture, and a turbine is mounted on the drive shaft in the central aperture. The turbine is rotated by the drive vortex as the drive vortex passes through the central aperture.
The device may also include a second plurality of baffles longitudinally mounted in the downstream chamber that operate to create a downstream extraction vortex rotating in a direction opposite to the first direction when the moving fluid enters the downstream chamber through the downstream chamber""s open sides. Additionally, a second plurality of hinged louvers may be positioned in the openings between the second plurality of baffles, encircling a downstream central vortex chamber. The second plurality of louvers permit entry of the moving fluid into the downstream central vortex chamber only when the fluid is rotating in the direction opposite to the first direction. They also prevent the fluid from exiting the downstream central vortex chamber through the sides of the device. In this manner, the turbine is rotated by the drive vortex as the drive vortex passes through the turbine and reverses direction to match the direction of the extraction vortex.
For high-wind conditions and when utilized with water, the drive vortex and extraction vortex may rotate in the same direction. The first plurality of hinged louvers encircle the upstream central vortex chamber, and the second plurality of hinged louvers encircle the downstream central vortex chamber. The first plurality of louvers permit entry of the wind or water into the upstream central vortex chamber only when the fluid is rotating in the first direction. Likewise, the second plurality of louvers permit entry of the wind or water into the downstream central vortex chamber only when the fluid is rotating in the first direction. Both sets of louvers also prevent the fluid from exiting the vortex chambers through the sides of the device.